A major mission of this group involves the basic research and service functions of NMR instrumentation provided to NIDDK scientists of the Laboratory of Bioorganic Chemistry, Laboratory of Medicinal Chemistry, other NIH laboratories and, to a limited extent, to scientists of other institutes. Assistance in the solution to structural problems is rendered on request. Provide critical interaction as well as extensive collaboration with other scientists in this Institute. Two collaborative projects that involve the use of various NMR techniques and molecular modeling are currently underway. These include structural elucidation of biologically active substances isolated from natural sources (in collaboration with Dr. John Daly's group) and conformational studies of structurally altered DNAs resulting from chemical modification by diolepoxides metabolically formed from known chemical carcinogens, such as benzo[a]pyrene (BaP) (in collaboration with Dr. Donald Jerina's group). It is hoped that the information obtained in the latter study shall shed some light on the structural role of these carcinogens may play in the cell transformation.